Disconnecting switch



Patented July 29, 1941 UNlTED STATES PATENT OFFICE iils'ooNNiii iiil SWITCH I.

Westinghouse Electric & Manufacturing Com: pany, East Pittsburgh, Pa., a corporation of Pennsylvania 19 Claims.

My invention relates generally to electric circuit interrupters and particularly to stop mechanisms for disconnecting switches.

Where disconnecting switches, particularly double-throw disconnecting switches, are mounted vertically, that is, where the movable blade is mounted for movement in a vertical plane, it may be necessary, or highly desirable to provide a positive 90 stop for the blade which can be disengaged, when desired. A stop of this sort prevents the blade from accidentally falling against the lower contact or other parts therebelow, and of course the action of gravity prevents unintentional engagement of th blade with the upper contact.

Heretofore stops of this type have been used, but have been relatively complex and have required rather extensiv machining or other alterations to existing standard switch blades to adapt them to receive the stop mechanisms employed heretofore.

It is, therefore, an object of this invention to provide a relatively simple and inexpensive releasable stop mechanism for disconnecting switches which will not require any machining operations or alterations to standard blade structures, and which can be applied to such blades by unskilled workers.

It is a further object of this invention to provide a disconnecting switch with a positive midposition stop requiring an additional operation to be performed by the operator to release the look.

It is also an object of this invention to pro vide a switch lock which when released is capable of automatically resetting itself by mere movement of the switch to its original position.

It is still a further object of this invention to provide a stop as an attachment for disconnecting switches of either the single or double-throw type, or the front or rear connected type.

These and other objects of my invention will be made more apparent upon consideration of the following specification taken with the attached drawings wherein are embodied the principal features of my invention. Referring to the drawings:

Figure 1 of the drawings is a side view of a double-throw disconnecting switch having my novel stop means applied thereto.

Fig. 2 is a front view of the switch shown in Fig. 1.

Fig. 3 is a fragmentary sectional View of the pivoted end of the movable contact blade of the switch shown in Figs. 1 and 2 and illustrating in detail my novel stop means with the blade in stopped position approximately 90 rom the position shown in Fig, 1.

Fig. 4 is a View similar to Fig. 3 showing the stop latch in a released position.

Fig. 5 is a view similar to Fig. 3 showing a modified type of pivot tongue for th movable blade.

Fig, 6 is an enlarged sectional View taken on the line VIVI of Fig. 2 looking in the direction of the arrows; and,

Fig. '7 is a fragmentary rear view of the pivoted end of the blade showing the stop means applied thereto.

In the embodiment of my invention shown, I have illustrated a Vertical support member 2 which may compris a channel member as shown, or a panel-board on which is mounted three vertically spaced insulators l, 6 and 8. The insulators are secured to the support 2 by means of projecting base flanges 5 on the insulators and bolts 1 passing through the flanges and engaging the support 2. The upper insulator member 4 is provided with a fixed contact tongue 16 of suitable conducting material such, for example, as copper or the like, and is also provided with an upwardly extending terminal part Ill. Th lower insulator 8 is provided with a fixed contact tongue l8 of suitable conducting material and a downwardly extending terminal part l2. The intermediate insulator 6 is provided with a fixed pivot tongue 20 of suitable conducting material which includes a part extending centrally rearwardly through the insulator 6 beyond the inner end thereof and terminating in a terminal part 14 for connection to a lead at the rear of the support 2.

The movable contact blade 22 is of th split blade type and includes the spaced parallel sides 24 composed of suitable conducting material, such, for example, as copper or the like. The blade 22 is pivoted at one end on the pivot tongue 20 with the tongue located between the sides 24 of the blade, by means of a bolt 26 passing through the blade and the pivot tongue. Resilient washers 28 are provided between the head of the .bolt and the nut associated therewith and the outer sides of the movable blade 22.

The other end of the blade 22 is provided with an operating portion 30 having an aperture 32 designed to be engaged by an operating hook stick or the like. Adjacent the outer end of the blade 22 there is provided a bolt 34 extending through the blade and having washers 36 thereon engaging the outer sides of the blade.

The bolt Ed is designed to engage in a groove 38 provided in the upper contact tongue l5 or a groove 4e provided in lower contact tongue E8. The grooves 38 and 46 are provided with outwardly flared extremities 42 and 44, respectively, to ensure entrance of the bolt 34 into the inner portion or" the groove.

The fixed pivot tongue 22 is provided with an integral stop portion 36 which is located slightly below the blade pivot 26 and projects forwardly therefrom. In this type of switch, wher at least the central terminal is connected at the rear of the switch support, the fixed stop 4'5 can be located eccentrically oi the blade pivot because the connection to the central terminal is made centrally of the insulator 6 and hence can be made from either side of the tongue without changing the position of the tongue.

The blade 22 is a standard type employed in single throw switches, as disclosed in the patent to H. J. Crabbs and H. L. Rawlins, No. 2,224,380, December 10, 1940, on an application filed May 17, 1939, and assigned to the same assignee of this invention. This blade is provided with pairs of spaced apertures 43 and 58 extending through both sides of the blade and located adjacent to, but spaced from, the blade pivot 26.

My stop means is designed as an attachment to such standard blade structures and is constructed so that it may be attached to such blade structures without altering the blade structure in any manner, the stop attachment being merely clamped onto the blade proper, use being made of the spaced apertures in the blade to assist in properly locating the attachment relative to the blade.

The attachment proper consists of a pair of side plates 52 which are identical in structure and include spaced projections 56 extending laterally from opposite sides of each plate. These projections are designed to fit in apertures 48 and 5i? to properly locate the attachment on the blade. It is obvious that any one plate 52 may be applied to either side of the blade since they are identical in structure.

The plates are secured in position on the blade by two bolts 58 and The bolt 6% passes through both plates and through a spacing sleeve 62 located between the plates and has a nut 64 bearing on a lock washer 68 to tighten the plates against the spacing sleeve 62. The spacing sleeve 62 prevents drawing up the nut 54 sufficiently to unduly contract the sides of the split blade 22. The bolt 58 is provided with a nut 68 bearing against the lock washer l8 interposed between the nut and the plate 52.

Rotatabiy mounted on the bolt 53, I have provided a latch member 72. The latch member includes an elongated portion '16 terminating in an enlarged ring portion '58 for the reception of a hook stick operating member or the like. Spacing sleeves i i are provided on opposite sides of the latch E2 on the bolt 58 and these together with the latch prevent drawing up of the nut sufficiently to unduly draw together the sides of the blade H. The latch is provided with a laterally extending portion 89 terminating in two stop portions 62 and 84 which are spaced from each other. A coil spring 85, formed of suitable resilient material, such, for example, as bronze or the like, has one end thereof extending through an aperture 88 in a web portion 98 of the latch, and has the opposite end thereof coiled about a pin Bl secured to the plates 52. The pin 9i has reduced end portions fitting apertures in the plates 52 and a grooved central portion 93 to receive the spring.

In the operation of the embodiment thus far disclosed, when the switch blade is moved from the position shown in 1, it can be moved downwardly until the stop portion 86 of the latch engages the fixed stop member as shown in Fig. 3. If it is desired to move the switch from this position downwardly into engagement with the lower contact it, it is necessary to insert a hook stick operating member or the like in the latch hook eye and exert a pull thereon in an outwardly and downwardly extending direction, whereupon the latch will be moved against the action of spring 8'5 about its pivot 58 in a counterclockwise direction to the position shown in Fig. 4, whereupon it is obvious that the stop portions 82 and 84 of the latch will clear the fixed stop and permit further downward movement of the switch blade. The fixed stop d6 is provided with a curved cam portion 84 on its lower side, so that upon movement of the switch blade from the lower contact past its midposition toward the upper contact, it is readily apparent that the stop portion 82 will engage the cam portion 95 on the fixed stop and raise the latch against the action of spring 85, and allow it to pass by the fixed stop whereupon the spring will reset the latch in the position shown in Figs. 1 and 3 with the spring maintaining that portion 522 of the latch adjacent the hook eye 18 in contact with the spacing sleeve 62. It is to be noted that the spacing sleeve 82 limits the movement of the latch in the direction in which it is urged by the spring 85, and that this same spacing sleeve 52 is engaged by the stop portion on the latch to limit movement of the latch in the opposite direction.

The modification illustrated in Fig. 5 is identical with the species already described, and like reference numerals are used thereon, except for the center insulator 9! which is provided with a med pivot tongue 98 having a side terminal H25 instead of a central terminal l l as illustrated in connection with the first embodiment described. The side terminal we is used where it is desired to make all the connections to the switch at the front of the switch support. In this event, it may be desired to make the connection to the center terminal at either side of the terminal. In other words, the terminal portion I55 may be placed at either side of the insulator Inasmuch as this is a special construction, the fixed pivot tongue is provided with a special stop )2 which is centrally positioned with respect to the blade pivot so as to be in the same relative position whether the terminal N30 is mounted at one side of the in ulator 9G or on the opposite side.

In this embodiment of my invention, when the blade is moved from the upper position downwardly, the latch stop portion 32 engages with the fixed stop I92 at the 99 open position of the switch blade and the latch portion 34 merely has the function of limiting the releasing motion of the latch. It is obvious that in this embodiment, as well as in the preceding form of my invention, when it is desired to move the switch blade beyond or below the position shown in Fig. 5, a pull on the hook eye '58 in a downward and outward direction will cause movement of the latch in a counterclockwise direction about its pivot 58 and remove the stop portion 82 of the latch from engagement with the fixed stop H12 and permit movement of the switch blade into engagement with the lower fixed contact.

The fixed stop I02 is provided with a lower inclined cam side I03 so that on movement of the switch blade from a lower position to an upper position, the stop portion 82 of the latch will engage the inclined side I03 of the fixed stop 32, and upon continued upward movement of the blade the latch will be moved in a counterclockwise direction with the latch contact portion 82 riding up the inclined portion 13 of the fixed contact until it clears the same, whereupon the spring 86 will reset the latch by causing the engagement of the neck portion 92 thereof with the sleeve 62.

It is apparent that I have provided as an attachment for a standard type of switch blade a stop means for positively limiting the opening movement of such blades which stop is releasable to permit further movement of the blade, and, particularly in double-throw types of switches to permit the blade to be engaged with the second set of stationary contacts. It is further apparent that my attachment can be applied to an existing standard type of blade without requiring any modification of. the blade structure, and without requiring any special skill to apply the same, there being but two bolts required to secure the same in position.

My attachment is equally adapted to single or double-throw switches. In its relation to double-- throw switches, it should be noted that the at tachment is constructed with a plurality of stop portions 82 and 84 on the latch so that it is adapted for either a front or rear connected type of switch.

When my attachment is positioned on a switch blade the stop latch 12, together with all parts associated therewith, such as the spring as and its motion limiting means 62, are all located between the sides 24 of the split blade type of contact member. Also, the location of the fixed stop member 45 between the blades 24 of the movable split blade results in a stop structure, the engaging stopping portions of which engage in a plane passing centrally through the switch, so that no off-center forces are encountered which might tend to bend the switch blade or fixed contact portions, which parts, if constructed of copper or a like substance, are relatively easily bent;

this results, generally, in an extremely stable and rugged structure.

Because of the interchangeability of plates 52, the number of parts that it is necessary to stock, to supply demands for this stop arrangement, is materially reduced.

It is obvious that I have provided a stop which is simple in design and of relatively few parts and which is easily adapted to many types of ex isting switches.

Having described preferred embodiments of my invention in accordance with the patent statutes, I desire that my invention be given as broad an interpretation as possible, since it is obvious, particularly to persons skilled in the art that many modifications and changes may be made therein, without departing from the broad scope of my invention, and I do not wish to be limited to the particular structures described herein except as specifically stated in the following claims.

I claim as my invention:

1. In a stop attachment for an electric switch blade, separate spaced opposed securing member for securing a switch blade therebetween, means carried by said members for securing the 1nembers in operative relation to a switch blade, said means positioned to lie without the confines of said blade, positioning means on at least one of said members adapted to engage the blade to positively position the stop relative to the blade, and stop means carried by said members.

2. In a stop attachment for an electric switch blade, spaced opposed securing members for securing a switch blade therebetween, means carried by said members for securing the members in operative relation to a switch blade, said means positioned to lie outside the confine of said blade, projections on at least one of said members adapted to engage in apertures provided in the blade to position the stop relative to the blade, and stop means carried by said members.

3. In a stop attachment for a split blade switch, spaced opposed securing members for securing a split switch blade therebetween, means for securing the members in operative relation to a switch blade, and stop means carried solely by and between said members so as to be located between the sides of a split blade when the attachment is secured in operative relation to the blade.

l. In a stop attachment for an electric switch blade, spaced opposed securing members for securing a switch blade therebetween, means carried by said members for securing the members in operative relation to a switch blade, and a movable stop latch carried by said members, said latch being spring-urged in one direction, an abutment carried by said members to limit movement of the latch in said one direction, and a projecting operating part on the latch whereby it can be moved away from the abutment.

5. In a stop attachment for an electric switch blade, spaced opposed securing members for securing a switch blade therebetween, means carried by said members for securing the members in operative relation to a switch blade, and a movable stop latch carried by said members, said latch having spaced projecting stop portions.

6. In a switch, the combination of a base, a contact blade movably secured to the base, a stop member carried by the base, supporting means detachably mounted on said blade, a movable latch and means for limiting movement of said latch all mounted on said supporting means independently of said blade, said latch being movable to and away from a position where it will engage said stop member upon movement of the contact blade.

7. In a switch, the combination of a base, a contact blade movably secured to the base, a. stop member carried by the base, supporting means dctacl'iably mounted on said blade, a latch movable to from. a position in which it may engage saic stop member, a stop for the latch for defining said position, and resilient means maintaining th latch against said stop, all mounted on supporting means independently of said blade.

8. In a switch, a pivotally mounted switch blade having spaced apertures adjacent its pivot, supporting means frictionally mounted on the blade and having spaced projections adapted to be received in the blade recesses to properly position the supporting means relative to the blade, and latch means mounted solely on said supporting means and adapted to releasably engage a fixed stop member to limit opening movement of the lads.

9. In a switch, a pivotally mounted switch blade having spaced apertures adjacent its pivot,

supporting plates at opposite sides of the blade and having spaced laterally extending projections adapted to enter the blade apertures to position the plates relative to the blade, means positioned outside the contour of said blade and connecting said plat s to secure them in position on said blade, and a lat a movably carried by said plates for releasably engaging a fixed stop member.

l0. In a switch, the combination of a movable switch blade, a latch movably mounted on said blade, a movement lii ing member on the blade, a plurality of stop portions on said latch and spaced in the direction of movement of said blade so as to be engageable, respectively, in one position of the latch with fixed stops provided on different types of switch bases, at least one of said stop portions being engageable with said member to limit movement of the latch away rom said one position.

11. In a switch, the combination of a movable switch a latch movably mounted on said blade, a movement limiting member on the blade, a plurality oi spac d stop portions on said latch engageable, respec- "ly, in on position of the latch with fixed stop provided on different types of switch bases, l .st one of said stop portions being engageable 1t 1 member to limit movement oi the latch away from said one position, said latch having an operating part extending beyond the blade and spaced from said one stop portion so as to be engageable with said member to limit movement of the latch to said one position.

12. In a switch, the combination of a movable switch blade, a latch movably mounted on said blade, a movement limiting member on the blade, a plurality oi spaced stop portions on said latch engageable, respectively, in one position of the latch with fixed stops provided on different types of switch bases, least one of said stop portions being engageable with said member to limit movement or" the latch away from said one position, sai' latch having an operating part extending bey the and spaced from said one stop p01 tron and on the other side of said member so as to engage said member to limit movement or" the latch to said one position, and resilient means maintaining said operating part against said member to resiliently maintain the latch in said one position.

is. In a switch, a fixed contact, a movable contact blade engageable with said contact, supporting means detachably mounted on the blade and carrying a movably mounted latch movable to and from a position in which it is engageable with a fixed stop at an open position of the blade, stop means to define said latch position, and resilient means maintaining the latch in engage ment with said stop means, said latch, stop means and resilient means carried by said supporting means, and a hook eye on the latch projecting from said blade and supporting means.

14. In a double-throw switch, a blade pivotally mounted for movement in an upright plane, fixed contacts above and below the blade pivot so as to be selectively engageable by the blade, 9. fixed stop adjacent the blade pivot, releasable stop means spring-urged to a position to engage said fixed stop at a mid-position of the blade, said stop means being entirely mounted on a support which embodies spaced members between which the blade is detachably secured.

15. In a stop attachment for an electric switch blade, spaced opposed securing members adapted to be mounted at opposite sides of a switch blade, spaced securing means adapted to clamp said members to said switch blade, said securing means being spaced apart a greater distance than the width of the switch blade on which said attachment is adapted to be mounted, and said members also including means for movably supporting a stop member therefrom.

15. In a stop attachment for an electric switch blade, spaced opposed securing members adapted to be mounted at opposite sides of a switch blade, spaced means connecting said members for securing said members at opposite sides of a switch blade and for movably supporting a stop means, respectively, said means positioned to lie beyond the confines of said blade when said attachment is secured in position.

17. In a stop attachment for a switch blade, a pair of identical securing members for supporting a stop means and adapted to be secured on opposite sides of said blades, means spaced apart a r distance than the width of said blade for rig said members thereto, and intermediate positioning lugs projecting from opposite sides of each of said members for engaging positioning apertures in said blades, to prevent relative sliding movement of said blade and members.

18. A supporting attachment plate for switch blades including at least a pair of mounting aperttres spaced apart a distance greater than the width of said blades, and intermediate positioning projections on said plate on opposite sides thereof.

19. In a stop attachment for an electric switch blade, spaced opposed securing members for securing a switch blade therebetween, means carried solely by said members for securing the members in operative relation to a switch blade, said means being positioned to be beyond the confines of said blade when said attachment is secured in position, and stop means movably supported by said members at a point outside the confines of said blade for movement thereof across said blade.

HERBERT J. CRABBS. 

